The S/390 Computing System offered by International Business Machines Corporation currently uses a 12 channel data bus known as a self-timed interface (STI) for many applications within the system architecture. For example, STI is typically used as a connector between a memory bus adapter and an input/output (I/O) subsystem. Radiated electromagnetic noise from copper STI interfaces and external noise coupled into the interfaces from other components in the system pose significant design challenges. As data rates increase and bus lines become longer, these problems become more significant making it difficult to maintain system integrity along the bus. For example, current STI links are limited to about 20 meters distance.
Prior United States Letters Patents discussing STI data buses have principally been directed to copper interconnections. For example, reference U.S. Pat. Nos. 5,522,088; 5,651,033; 5,867,648; 5,787,094, and 5,581,566, each of which is hereby incorporated herein by reference in its entirety.
As computer systems become larger and more complex, the amount of data which can be conveyed over an electrical backplane or over copper wire interconnections between processor chips, via for example a memory bus adapter and I/O subsystem, becomes a bottleneck to improved performance.